Spy agencies across Europe are reportedly working on mass surveillance of Internet and phone traffic, Britain's Guardian newspaper reported on Saturday.

The paper reported that according to documents leaked by fugitive former U.S. National Security Agency (NSA) contractor Edward Snowden, the spying methods included tapping into fibre optic cables and working covertly with private telecommunications companies.

The Guardian named Germany, France, Spain, Sweden and the Netherlands as countries where intelligence agencies had been developing such methods in cooperation with other agencies including Britain's GCHQ.

Ironically, Germany and France have been protesting about U.S. mass surveillance of European communication networks revealed by Snowden since June. There is also a recent revelation that the NSA monitored the mobile phone of Chancellor Angela Merkel.

The Guardian said GCHQ files leaked by Snowden showed the British agency taking credit for advising European counterparts on how to get around domestic laws intended to restrict their surveillance powers.